1. Technical Field
Example embodiments of the present invention relate in general to a wireless communication technology and more specifically to a method of reassigning an association ID (AID) and an apparatus for performing the same, which allow an optimal operation of a wireless local area network (WLAN) system according to a change in characteristics of a terminal.
2. Related Art
Various wireless communication techniques are being developed along with the recent development of an information communication technology. In particular, wireless local area network (WLAN) is a technology that can provide a wireless connection to the Internet in a limited service area such as a home or office building using portable terminals, for example, a personal digital assistant (PDA), a laptop computer, and a portable multimedia player (PMP) based on a wireless frequency technology.
Standards for WLAN technology is developed and standardized by IEEE 802.11 working group (WG) in the Institute of Electrical and Electronics Engineering (IEEE) 802.11. IEEE 802.11a provides a maximum PHY data rate of 54 Mbps using 5 GHz unlicensed band. IEEE 802.11b provides a maximum PHY data rate of 11 Mbps by using direct sequence spread spectrum (DSSS) in 2.4 GHz band. IEEE 802.11g supports a maximum PHY data rate of 54 Mbps by using orthogonal frequency division multiplexing (OFDM) in 2.4 GHz band. IEEE 802.11n provides a maximum PHY data rate of 300 Mbps using 40 MHz bandwidth with two spatial streams and a maximum PHY data rate of 600 Mbps using 40 MHz bandwidth with four spatial streams.
Along with the wide deployment of WLAN and the diversification of applications using WLAN, new WLAN techniques are increasingly needed to support higher throughput than IEEE 802.11n. Very high throughput (VHT) WLAN is one of 802.11 WLAN techniques, which is proposed to support a data processing rate of 1 Gbps or more. In particular, IEEE 802.11ac is developed as a standard for providing a very high throughput on the 5 GHz band, and IEEE 802.11ad is developed as a standard for providing a very high throughput on the 60 GHz band.
In systems based on the WLAN techniques, an access point assigns individual association IDs (AIDs) to terminals in the order in which the terminals are associated with the access point. However, when 6,000 or more terminals are required to be supported (for example, 802.11 ah), the access point groups terminals having similar characteristics and assigns AIDs to the grouped terminals to perform effective management.
That is, the access point may adjust a network traffic amount and a simultaneous channel access amount by grouping a plurality of terminal in units of pages and setting traffic indication map (TIM) elements at different periods.
When the traffic is overloaded at a TIM setting period, AIDs are needed to be reassigned to change some of terminals in a specific page group to another page group. In addition, when a service type or a traffic characteristic of a terminal is changed, the AID is needed to be correspondingly reassigned.
In order to the above-described need, research is being conducted on an AID assignment request, but a detailed method for AID assignment is not yet revealed.